The present invention relates in general to a 3D contact measuring device and in particular to a 3D contact measuring device, which is in particular suitable for tactile sensing workpieces in the direction of a measuring axis and transverse to the measuring axis.
In general, such 3D contact measuring devices comprise a sensing arm, which projects from the housing and which bears a sensing tip, wherein said sensing arm can be moved relative to the housing in the direction of a measuring axis and can be pivoted in all directions about the measuring axis, and a measuring device for detecting the deflection of the sensing arm. Typically, common mechanical gauges are used for this purpose. For the most part, they comprise a round scale and an analog display, wherein the longitudinal movement of a measuring bolt is transferred to a rotatable indicator of the gauge display by means of a toothed rack, which is attached to an inner end of the measuring bolt, and by means of a gear transmission, which is driven by means of the toothed rack. Gauges comprising a digital display are also used.
The 3D contact measuring devices can be used, e.g., for adjusting the zero point of a numerically controlled machine tool in relation to the workpiece, which is to be machined. For this purpose, the contact measuring device is clamped into a machine tool spindle and is moved with its sensing tip to a reference surface of the workpiece. By further advancing the machine tool spindle, the sensing arm is then pushed away from the workpiece, until the indicator of the gauge reaches its zero position.